In the technical field of a flexible printed circuit (FPC), some measures are required to be taken against electromagnetic interference (EMI) in order to promote improvement in transmission characteristics or enhancement in transmission speed. In order to reduce EMI, a multilayer FPC is proposed. For example, it is proposed to place a signal layer between two GND layers. A general multilayer FPC is constituted by placing two or more circuit substrates one upon another. The circuit substrates placed one upon another are bonded together by adhesive layers, each containing adhesive and spreading over between any two adjacent circuit substrates.
Here, adhesive may partially exude from any adhesive layer by the pressure exerted to bond the circuit substrates together. If a large quantity of adhesive should exude, some of the exuded adhesive may spread over a connector area to which electronic components are connected. Then, poor connection of electronic components may arise, and the yield in the manufacture of FPCs may decrease.